"Our organisation is founded on the principle of anti-corruption," he said.
"No one found guilty of corruption... will wear the beret," he said, sporting a bright red EFF-branded beret.
Malema is facing corruption charges in the Polokwane Magistrate's Court.
He is accused of making nearly R4m from corrupt activities. He is out on bail of R10 000 and faces charges of fraud, corruption, money-laundering, and racketeering.
On Thursday, Malema said thousands of South Africans had responded to the "clarion call" the EFF made on 11 June, asking them for contributions on "what is to be done".
"It is no secret that an absolute majority of all those who have responded are saying that EFF should be a radical, left, anti-capitalist and anti-imperialist movement with an internationalist outlook that should contest elections in South Africa."
The expelled ANC Youth League leader said the EFF was changing the political climate, as it was commonly held that it was "cold outside the ANC".
"But we are making it warm outside the ANC."
Attempts to discredit the fledgling organisation would not succeed, Malema said.
"We've got the will. We are not material-driven. You can take away everything but you cannot take our souls."
Malema said that EFF was "not my organisation" and it did not "want to be worshippers of an individual".
There was no such organisation as the ANC, as it had become the "ZANC", as President Jacob Zuma had subsumed the ruling party.
"The organisation can't call the president to order."
‘A different plan’
Malema also drew a distinction between the EFF and other ANC breakaway parties.
"We are not like Agang [SA] and all of them... We have a completely different plan."
This plan included the non-negotiable principles of land expropriation and nationalisation of mines, both without compensation.
The EFF sought to move away from a discourse of reconciliation to one of justice. It would hold a conference in Soweto on 26 and 27 July to work out its policies and manifesto.
"[The EFF is] the people's organisation, inspired by people's suffering on the ground."
It would embrace an "anti-capitalist and anti-imperialist ideology", and aspired to non-racialism and non-sexism.
While white capitalist monopoly was an enemy of the EFF, Malema said "no one is going to be driven into the sea".
"You are going to be forced to share."
The EFF was strongly opposed to foreign land ownership.
"[There will] never be foreign ownership of land, that is what we will do when we take over."
Malema warned South Africans to prepare for the sacrifices that would come with the EFF's envisaged revolution.
"There will be a day [when] we will wake up without bread on the shelves. We will learn to make our own bread."
Zimbabwe had been ready to "take the pain" associated with revolution, Malema said.
He lambasted several news organisations at the press conference, claiming that SABC news was "run from [ANC headquarters Chief Albert] Luthuli House".
"I know how we used to run them when we were there."
The Gupta family-owned The New Age was not a newspaper, but a newsletter.
Asked to comment on reports that a house of his in Polokwane would be auctioned later this month, Malema said he did not own a house in Polokwane.
On Thursday, The Sowetan reported that the house would be put on auction as part of efforts to recoup the R16m he owes the SA Revenue Service (Sars).
His household goods were sold for R54 000 in February and in mid-May his incomplete mansion was sold for R5.9m, R2.3m more than he paid for it in 2009. In June a farm belonging to him was sold for R2.5m.
Malema appealed for donors to support the organisation, but said the EFF would remain a grassroots organisation, with "no fancy rallies".